1. Field of the Invention
The present invention generally relates to beds, and, more particularly, to foldable field stretchers.
2. Description of Related Art
It is well known that simple field stretchers formed from canvas stretched between two parallel, rigid shafts can be used for carrying sick, wounded, or dead persons from remote locations in the field. For example, U.S. Pat. No. 4,124,908 discloses a rescue and transportation device which includes breakaway poles extending through slots formed on opposite sides of a flexible bottom. Although such poles can help evacuation workers to lift and support the patient during transport, they also make the device more difficult to store and maneuver in crowded or restricted areas. U.S. Pat. No. 5,701,619 discloses a stretcher with similar drawbacks formed from a cellular plastic material with internal channels under the patient for holding longitudinal glass-reinforced plastic stiffening elements.
U.S. Pat. No. 4,723,327, on the other hand, discloses a patient mover without rigid supports having an integral, one-piece, continuous handle strap that extends around a channel in the perimeter of a rectangular sheet. The handle strap is accessible at each of the four corners of the sheet and is self-adjusting to the patient's position and the carriers' needs. However, since the handles move relative to the patient, this design can be unstable. U.S. Pat. No. 5,214,813 discloses another rectangular stretcher with reinforced handhold patches at each comer that include folded flaps for protecting users' hands. However, such stretchers do not always provide adequate support beneath the patient.
U.S. Pat. No. 5,121,514 discloses a rectangular emergency support device with increased rigidity in its weight-bearing portion which includes a unitary, or segmented, support layer of polymeric sheeting. The support layer warps slightly from side to side but resists enveloping or imposing radially directed compression forces on the patient. Hand grips are formed on the device by a length of nylon strapping extending axially through parallel loops on each side of the device.